1. Field of the invention
The present invention relates to a method and a device in which an original document is transported to an exposure station circularly, and a copying apparatus with said document transporting device.
2. Description of Related Art
Conventionally, the above-described document transporting device has been proposed in various prior arts such as in U.S. Pat. No. 3,770,348, U.S. Pat. No. 4,445,682, U.S. Pat. No. 4,465,271, and U.S. Pat. No. 4,816,865. These devices generally comprise a plurality of bypass paths for efficient document circulation and transportation and are so arranged to enable selection of the proper document circulating and transporting path according to a document size.
In those conventional circulating document transporting devices, means for changing the length of the circulating transporting path have been provided on only one side of the exposure station. In such construction, the number of change-over transporting paths equalling to the number of the circulating transporting paths would be required. And if more types of the circulating document transporting paths of different lengths are to be provided, it becomes necessary to increase the number of the change-over transporting paths in accordance with the circulating transporting paths. That causes an increase of parts as well as the complexity of the device.